We report laser cooling of fermionic 40K atoms, with temperatures down to (15+/-5) μK, for an enriched sample trapped in a magneto-optical trap and additionaly cooled in optical molasses. This temperature is a factor of 10 below the Doppler-cooling limit and corresponds to an rms velocity within a factor of 2 of the lowest realizable rms velocity (~3.5vrec) in three-dimensional optical molasses. Realization of such low atom temperatures, up to now only accessible with evaporative cooling techniques, is an important precursor to producing a degenerate Fermi gas of 40K atoms.
Physical Review A
- Pub Date:
- November 1999
- Optical cooling of atoms;
- Fermion systems and electron gas;
- Condensed Matter - Statistical Mechanics